Yarnlike product with spaced polymer rings

ABSTRACT

A generally twistless yarnlike product is kept coherent by means of circumjacent polymer rings applied at intervals, high bulk being achieved by a loop effect as the filaments or fibres are differently contracted between the rings. To make such a product and similar products bound with rings, a bunch of fibres or filaments is temporarily brought in twisted and revolving state, and strips of a polymer in fluid state are spun around by means of the revolution of the bunch.

United States Patent 1191 Rasmussen 1 Dec. 31, 1974 1 1 YARNLIKE PRODUCTWITH SPACED 3,116,588 1/1964 Breen et a1. 57/34 8 ux 3,402,096 9/1968Blanchette 57/ 140 .1 X POLYMER RINGS 3,446,002 5/1969 Kippan 57/140 R[76] Inventor: Ole-Bendt Rasmussen, T psty t 3,468,746 9/1969 Scheier57/140 BY 7, Copehhagen, Denmark 3,500,629 3/ 1970 Gliksmann et a1.57/140 BY X Filed: J y 0 3 3,626,684 12/1971 Hovls et a1. 57/140 BY [21]Appl. No.: 380,978 E Do Id E w k Primary xaminerna at ins RelatedApphcafion Data Attorney, Agent, or Firm-William J. Daniel [62] Divisionof Ser. No. 120,186, March 2, 1971, Pat.

[30] Foreign Application Priority Data [57] ABSTRACT Apr. 2, 1970Denmark 1664/70 A generally twistless yarnlike product is kept coherent[52] US. Cl- 140 J, 5 1 140 by means of circumjacent polymer ringsapplied at in- I 57/140 C tervals, high bulk being achieved by a loopeffect as 1 8 0, g the filaments or fibres are differently contractedbe- Field Of Search tween the rings. To make such a product and similar7/ 1 4 Q 140 157 157 S, products boundwith rings, a bunch of fibres orfila- 57/16 140 140 .1; 264/167, 174; 156/434 ments is temporarilybrought in twisted and revolving state, and strips of a polymer in fluidstate are spun [56] References Cited around by means of the revolutionof the bunch.

UNITED STATES PATENTS 4 1,909,192 5/1933 Taylor 57/ 140 C X 8 Claims, 5Drawing Figures PATENTEI] DEBS l 1974 sum 1 or 2' YARNLIKE PRODUCT WITHSPACED POLYMER RINGS This is a division, of Ser. No. 120,186, filed Mar.2, 1971, now U.S. Pat. No. 3,762,142, issued Oct. 2, 1973.

Yarns or yarnlike products are known which are kept together through abinding material instead of through twisting. These products are,however, either relatively stiff and compact, or they show littlecoherency, and their applications are therefore limitedrThe presentinvention aims at obtaining an adequate combination of volume,flexibility, resilience, and coherency.

It is known to extrude a bundle of filaments which are thereuponentwined with a thread of molten polymer from a nozzle rotating aroundthe bundle, whereby without actual twisting a yarn or yarnlike productis obtained with a structure simulating a twist.

The present invention relates to a yarn or yarnlike product consistingof filamentitious structures, kept in bunched relationship by means of acircumjacent polymer material. The characteristical features of the yarnor yarnlike product according to the invention are that saidcircumjacent polymer material forms rings which keep the bunch in acompact round shape within short zones, the intervening zones of thebunch being in a bulky state.

Due to the segmental arrangement where zones of strong bindingalternating with zones without any direct binding all theabove-mentioned properties can be obtained at the same time. The ringsshould preferably, but not necessarily, be adhesively bonded to thecircumferential portion of the bunch.

The lengths of the zones'supplied with rings should for most purposes bein a range between about 0.2 mm and 1 cm, while the lengths of theintervening zones should for most purposes be in a range between about 1mm and 5 cm. Dependent on the use, the bunch can consist of filamentsand/or staple fibres and/or fibrillated film and/or non-fibrillated,transversely compacted film and/or of ribbons and/or other fibrelike orfilamentlike structures. The product can further be a single,transversely compacted film kept in the shape of a bunch by means of therings.

An advantageous embodiment of the product according to the invention ischaracterized in that the filamentitious structures in each interveningzone have different lengths measured from ring to ring in the unloadedcondition of the yarn. This is generally obtained by different shrinkageof the filamentitious structures after the application of the rings, aswill be explained below. The relatively long fibres will be bent andwill hereby tend to elongate the product, while the relatively shortfibres will be straightened out and will tend to contract the length.There is hereby obtained a high and very stable volume.

An embodiment of the product according to the invention, of the typewhich comprises different lengths between the rings, is furthercharacterized in that said 1 lengths are shorter in the central portionof the bunch and longer in the outer portion of the bunch. Because ofthe order of this structure there is hereby obtained the most pronouncedvisual effect of the structure and generally also the highest volume.

An alternative embodiment. also of the type which comprises differentlengths between the rings, is characterized in that the distribution ofthe shorter and the longer filamentitious structures is at random.Although this arrangement generally produces a somewhat lower volume,the bulk is on the other hand generally more stable.

The random distribution can be obtained by blending staple fibres ofdifferent ability to shrink and making a raw-yarn herefrom inconventional manner. Another way to obtain random distribution is to laytwo network-formed, fibrillated films from different substances one uponthe other and compact the plied structure transversely.

It has been mentioned that the longer filamentitious structures and theshorter ones generally represent different amounts of shrinkage, andthese differences can be obtained by a variety of selections.

Thus in one embodiment the shorter filamentitious structures consist ofan elastomer, and the longer ones consist of a stiffer substance. Thisselection has the advantage that the elastic material easily elongatesuntil the elongation is stopped by the straighteningout of the stifferfilamentitious structures which will then provide a relatively hightensile strength. Further the elastomer will readily contract to theshorter length and thus the bulk will recover efficiently when thetension has been released. For apparel purposes and in other cases whenfine fibres are generally required, the elastomer should preferably be athermoplastic elastomer of the type where the stabilisation is due tocrystalline segments instead of real cross-linking, as for exampleextrudable polyurethane rubber.

In another embodiment the shorter filamentitious structures are crimpedbicomponent fibres or filaments, and the longer filamentitiousstructures are mono-component fibres or filaments. Crimped bicomponentfibres generally act like elastomer fibres and have the advantage thatthey are much easier to blend with other fibres (generally in uncrimpedstate), and

.thqqhp sep ar l selz uhsta JUKE Q h other hand, the tension instretched state at low elongations is generally lower.

When distinguishing between shorter and longer" filamentitiousstructures in the cases when some of the fibres are curled-upbicomponent fibres, what matters is, of course, not the lengths alongthe helices, but the lengths measured along the axes of the helices.

In still another embodiment the filamentitious structures arebicomponent fibres of different crimp. In this manner the product hasparticularly high extensability, but on account to some extent of thevolume.

Cut up to short lengths the product of the invention can with advantagebe used as an artificial feather or down, e.g. in pillows and quilts. Inorder to fit well to the shape of the body, the lengths shouldpreferably be as short as possible in proportion to the transverse span,and for this and similar purposes an embodiment of the product ischaracterized inthat it only comprises two rings.

Though the transverse coherency in the yarn or the yarnlike product issubstantially due to the rings, it should be understood that the productmay also be provided with a slight twist.

The polymer to form the rings can be supplied either in molten ordissolved or emulsified state, or in form of one or several prepolymers.Correspondingly the solidification can take place either by cooling orby evaporation of a solvent or of an emulsifier, or by coagulation ofthe emulsion, or by curing of the prepolymer(s).

The invention can be adapted to produce a product of particularly highbulk. For this purpose the filamentitious structures are oriented bystretching before the application of the polymer rings and maintainedoriented during the such application,'and that subsequently differentfilamentitious structures are subjected to different shrinkage todevelop a bulk. The best results are obtained by use of filamentitiousstructures from different substances which exhibit different tendenciesto shrinkage. The substances need not be from chemically differentpolymers, but may be from the same polymer but in different grades.

However, it is also possible to cause the different shrinkage by unevenheating (and/or swelling) of different portions of the bunch.

The invention will hereafter be described in further detail withreference to the drawings, of which FIG. 1 is a photo showing in 4 timesmagnification a yarn of the invention bound with rings and consisting ofbicomponent crimped fibres which are of different lengths between therings,

FIG. 2 is a schematical representation of the preferred embodiment ofthe product where the filamentitious structures have different lengthsbetween the rings,

FIG. 3 shows, in perspective and schematical view, a process line forbinding a bunch with rings at intervals,

FIG. 4, shown in longitudinal view, is a detail of the extruder die forthe spotwise supply of polymer in the line of FIG. 3,

FIG. Sis a transverse section along I--l of FIG. 4.

In FIG. 2 a bunch of many filaments or staple fibres are bound togetherby the ring-formed entwined polymer strips, 1, 2, and 3, which formrings. The filaments or staple fibres, 4, 5, 6, and 7 are comparativelylong, as measured from one edge of a ring to the adjacent edge of anadjacent ring. These long filaments or fibres form a kind of loops andtend to elongate the entire bunch, while the more contracted filamentsor staple fibres, 8 and 9, tend to make the entire bunch shorter. Forthe sake of clarity, the rest of the filaments, e.g. 10, are onlyindicated as whiskers in the immediate neighbourhood of the rings, butshould be understood as generally occupying the entire zone betweenadjacent rings with no or relatively few loose ends. Some of thesefilaments or fibres, which are only partly shown, should be relativelylong, and others relatively short. Of course, it is also possible to usea range of many different lengths in each intervening zone.

The filaments or fibres, 8 and 9, are shown as really straightened out,but could also be of helical configuration as obtained by shrinkage ofconjugantly spun filaments or fibres from two components inside-'by-side relationship. (Each filament or fibre will then alternatebetween left-turning and right-turning helices). In similar manner, theloop-forming filaments or fibres, 4, 5, 6, and 7 can also be of helicalconfiguration although they must of course be less contracted than 8 and9.

Due to the loop-effect the structure exhibits, as it has proven, a highand resilient bulk. Furthermore, the firm binding at intervals providesfor a high resilience in respect of bending of the yarnlike product.

In FIG. 3 a twistless raw-yarn or similar, 11, is shown taken from abobbin, 12, but could of course be taken directly from a card or anextrusion device. 11 can be any kind of raw-yarn or similar, even asingle, relatively narrow film. From a set of driven feed rollers, l3l4,

and 15 the yarn is fed into a zone where it is kept in twisted andrevolving condition by means of a falsetwist device consisting of thesection-formed, driven rollers, 16 and 17. These rollers rotate as shownby the arrows, 18 and 19, and at the same time each section,

when passing the nip, is moved at a constant velocity in the directionsshown by the arrows, 20 and 21, respectively, i.e. the two rollers, 16and 17 constantly act in different directions on the yarn, herebyproducing a false-twist. Having passed the nip, each section is revertedto be ready for the same twisting action when it again meets the nip.These reciprocations, synchronized with the rotations, are guided by aset of camdevices. For a more detailed description of the falsetwistrollers, see the article False Twist and Stretching Process for Tape, inPlastics Rubbers, Jan. 22, 1970. This device is particularly fast,enables simultaneous treatment of many yarns, and a high'tension in thezone of twist. It is of advantage to establish such a tension in orderto overcome the friction from the supply means which counteract therevolution of the yarn.

In the zone between the feed-rollers, 14-15, and the sectionformedrollers, 16-17, the yarn, here numbered 22, will be in twisted andrevolving condition, but having left the section-formed rollers, 14-15,the yarn, here numbered 23, will again be twistless. The application ofthe rings, 24, is carried out by means of a kind of printing roller, 25,which is rotated so as to follow the advance of the yarn, 22. Thisprinting roller, however, is also an extrusion die, see the moredetailed FIGS. 4 and 5. The molten polymer is fed from the extruder, 26,through a'fitting 27, and into a central die part, 28, which does notfollow the rotation of 25.

For the sake of clarity, FIG. 3 only shows the processing of one yarn,but in actual fact several yarns should be processed simultaneously, asit also appears from the construction in FIG. 4.

In order to distribute the molten polymer between i the different yarns,the central die part, 28, houses a distribution chamber, 29, suppliedwith a number of slots, 30, which are evenly distributed along thelength of the printing roller. Each slot, 30, feeds an array of radialchannels, 31, in the rotating roller, 25, each array of channelsterminating in a circular row of orifices from which the printing takesplace. There is sealing between the fixed central die part, 28, and therotating roller, 25, and the extrusion through each channel, 31, takesplace in pulsations when the orifice is in the position for printing.

In order to ensure a smooth distribution of the polymer in each spot,each row of orifices is placed at the bottom of a semi-cylindricalgroove, 32, the diametre of which is only slightly bigger than thediametre of the twisted yarn, 22. The resistance against the revolutionof the yarn is minimalized by only letting the yarn contact the printingroller over a short distance, however long enough to make the yarn turnnot less than one revolution around itself during the contact in orderto form a well-shaped ring.

To obtain this it is furthermore essential to rotate the printing rollerat such a speed that the orifices exactly or almost exactly follow theadvance of the yarn. For the sake of clarity, the drive is not reallyshown, but only indicated by the arrow, 33.

Further, the die is heated for the extrusion, but the heating elementsare not shown. Neither are shown the thread guides before the feedroller, 13, and before the printing roller, 25, which keep the differentyarns spaced apart and ensure a safe guiding of the yarns to thegrooves, 32.

Between the printing roller, 25, and the false-twist rollers, 16 and 17,the rings, 24,'are strongly cooled by means of a water spray or a waterbath (not shown). A cooling bath, however, must beso constructed thatany substantial hindrance against the revolution of the yarn, 22 isavoided.

To avoid squeezing of the rings, the section-forming rollers, 16, and17, must be coated with soft rubber, or a more practical measure is tosupply one or both surfaces with grooves which are spaced at the samedistance from one another as the distance between the rings, 24, at thesame time as the printing roller, 25, and the false-twisting rollers, 16and 17, are syncronized in such manner that the rings, 24, will fit intosaid grooves and a squeezing of the rings hereby will be prevented.

After the false-twist rollers, 16 and 17, follows a set of drivenpull-rollers, 36 and 37, which assist the falsetwist rollers, 16 and 17,in setting-up a tension in the yarn, 22, while the latter is guidedinrevolving state over the printing roller, 25. As already mentioned, thistension is set-up to overcome the resistance against said revolution.

If the raw-yarn, 11, consists of filaments, fibres or otherfilamentitious structures of different substances, and if there isestablished a high tension before and/or during the false-twist, thenthere will generally spontaneously develop a bulk when the tension isreleased in twistless state. This is indicated at 34 before the spoolingon the bobbin, 35, and is due todifferent shirnkage of the differentsubstances. To further promote such different shrinkage, an oven can beprovided for in the line after the rollers, 36 and 37, but a heattreatment to develop the bulk can of course also be carried out duringrespooling of the yarn or in the final textile product.

To produce short lengths for use as feather or down substitute, thebobbin, 35, is substituted by a cutting device, which is syncronizedwith the printing roller",

h so as to cut regularly between the rings.

Yarnlike products manufactured according to the invention may be appliedfor a great variety of textile and technical purposes, and theapplications range from the highest fineness used of yarn, i.e. aboutdenier, to the coarsest yarn, i.e. about 100 denier, with preference,however, for the range from about 500 denier to about 30.000 denier. Theexamples below illustrate different applications.

EXAMPLE 1 This example illustrates the use of the invention tomanufacture a bulked effect-yam for curtains.

The raw-yarn consists of bicomponent filaments from polypropylene andpolycaprolactame bonded in sideby-side relationship by means of a thinlayer of an ionomer polyethylene which exhibits adhesive properties. Theraw-yarn is produced by the method and apparatus explained in thearticle Split Film Gets a Second Look", in Textile Industries, Julyl969. Due to casual irregularities of the dieparts the fibres in theyarn exhibit different crimpability, after stretching, and thedistribution of the differences is almost at random. The average fibredenier is about 20 and the yarn denier about 4.000.

By means of a laboratory line as shown in FIG. 3, short rings ofpolypropyleneare applied at a mutual distance of 2 cm. The melt index ofthe polypropylene is 10 according to ASTM D 1238-62T, condition K. Inorder to obtain a smooth print it has proven advantageous to use such arelatively low-viscous grade. The rings are cooled in a water bath. Thefalse-twist is carried out with 6 turns per 10 cm.

The bulk is developed by heating to C in relaxed state by which each ofthe filaments crimps in helical manner, but to different degrees'Thelook of the yarn is almost as shown in the photo, FIG. 1. The yarnlikestructure is used as weft in a fabric with fine nylon threads as warp,whereby a very attractive visual effect is obtained.

EXAMPLE 2 This example illustrates theme of the invention to manufacturea feather substitute for filling of pillows or quilts. staple For thispurpose the raw-yarn should be a carded blend of 4 denier monocomponentpolyethyleneterephthalate staple fibres and 4 denier bicomponentpolyethyleneterephthalate staple fibres, again in a yarn denier of about4.000. The materials for the rings should be a copolymerofpolyethyleneterephthalate and polyethyleneglycol of melting point C andmelt index 2 according to the same ASTM specification, but condition E.The rings should be-applied as thin and short as possible and at aspacing of 4 cm. After elimination of the twist the yarn should be cutbetween the rings to short lengths, each comprising 2 rings, and thebulk developed by heating.

EXAMPLE 3 This example illustrates the use of the invention tomanufacture a grass substitute.

As raw-yarn is used two fiat, network-formed webs, each formed byneedle-fibrillation of oriented film. One is made from polypropylene andthe other one from polycaprolactame. Each has an average fibre denier ofabout 50 and a yarn denier of about 2.000.

The two flat networks which are taken from two spools are assembled oneon top of the other without any adhesion, and are fed into the line ofFIG. 3. The polymer for the rings, and the process is the same as inexample 1, but by means of wider orifices the rings are made about 3 mmlong, and the spacing between the rings is 1 cm.

The resulting product, after heat treatment at 120C, shows highresilience and a stable high bulk and is suitable as a tufting productfor sport-fields, etc.

I claim:

1. A yarnlike product formed of a plurality of filamentitious structuresarranged in a substantially untwisted elongated coherent bundle, saidbundle having at each of a plurality of spaced points along the lengththereof a distinct applied band of solid polymer extending as acontinuous ring around the periphery of a small localized compactsection of the bundle and holding said structures in said coherentbundled relation, the intervening sections of said bundle betweenadjacent pairs of rings being substantially greater in length than saidlocalized sections and having the filamentitious structures therein inloose unrestrained condition of substantially greater bulk than saidcompact sections.

2. The product of claim 1 wherein some of the filamentitious structuresin said intervening sections of said bundles are of a shorter lengththan the remainder of said structures whereby the latter assume a bulkycondition between said polymer bands.

3. The product of claim 1 wherein said filamentitious structures arestaple fibers. i

4. A product according to claim 2 wherein said structures of shorterlength are in the central region of the bundle and the remainder inthe'outer portion of the bundle.

5. A product according to claim 2 wherein the distribution of theshorter and the longer filamentitious structures is at random throughthe bundle.

crimped structures assume a bulky condition.

are generally non-- UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent N 3,857,230 Dated December 31, 1974' Inventoz-(s)Ole-Bendt RASMUSSEN' It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

In the Heading of the Patent under "Foreign Application Priority Data"in addition to Danish Application No. 1664/70 filed April 2, 1970, addMarch 3, 197 0 Denmark l04'D/70 Signed and sealed this 4th day'of' March1975.

(SEAL) Attest:

' C. MARSHALL DANN RUTH C. MASON v Commissioner of Patents AttestingOfficer 5 and Trademarks F ORM PC4050 (10-69)

1. A yarnlike product formed of a plurality of filamentitious structures arranged in a substantially untwisted elongated coherent bundle, said bundle having at each of a plurality of spaced points along the length thereof a distinct applied band of solid polymer extending as a continuous ring around the periphery of a small localized compact section of the bundle and holding said structures in said coherent bundled relation, the intervening sections of said bundle between adjacent pairs of rings being substantially greater in length than said localized sections and having the filamentitious structures therein in loose unrestrained condition of substantially greater bulk than said compact sections.
 2. The product of claim 1 wherein some of the filamentitious structures in said intervening sections of said bundles are of a shorter length than the remainder of said structures whereby the latter assume a bulky condition between said polymer bands.
 3. The product of claim 1 wherein said filamentitious structures are staple fibers.
 4. A product according to claim 2 wherein said structures of shorter length are in the central region of the bundle and the remainder in the outer portion of the bundle.
 5. A product according to claim 2 wherein the distribution of the shorter and the longer filamentitious structures is at random through the bundle.
 6. A product according to claim 2 wherein the shorter filamentitious structures consist of an elastomer, and the longer ones are generally non-elastomeric.
 7. A product according to claim 2 wherein the shorter filamentitious structures are crimped bicomponent fibres or filaments, and the longer filamentitious structures are mono-component fibres or filaments.
 8. The product of claim 1 wherein said structures are crimped and some of said structures have a different degree of crimp from others thereof whereby the lesser crimped structures assume a bulky condition. 